Background Automotive repair workers are exposed to a wide variety of volatile organic compounds (VOCs) during painting operations, which poses significant health risks. Biomonitoring can directly reflect the internal body burden of these compounds. Therefore, it is essential to develop an analytical method for simultaneous determination of VOCs in the urine of automotive spray painting workers. Objective To establish a static headspace gas chromatography-mass spectrometry (GC-MS) method for simultaneously determining 22 VOCs in the urine of spray painting workers in automotive repair enterprises. Methods An automatic headspace sampler was used for the pretreatment of urine samples. The headspace conditions as well as the chromatographic and mass spectrometric conditions of static headspace GC-MS were optimized. The separation of 22 VOCs was achieved by optimizing the temperature program. Sensitivity was enhanced by optimizing the quantitative ions. The signal response of VOCs was improved by optimizing the headspace equilibrium temperature, equilibrium time, and the amount of inorganic salt added. The method's detection limit, lower limit of quantification, accuracy, precision, and stability were tested using blank urine samples spiked with standards. Additionally, the method was applied to examine 40 urine samples collected from painting workers in automotive repair enterprises in Tianjin. Results In this study, the headspace equilibrium temperature was set at 80 ℃, the equilibrium time was 30 min, and the salt addition amount was 2.0 g. A DB-624ms chromatographic column was selected for the separation of 22 VOCs. The initial temperature of heating program was 50 ℃, maintained for 15 min, and then increased to 85 ℃ at a heating rate of 10 ℃·min⁻¹ for 10 min, followed by increasing to 90 ℃ at a heating rate of 5 ℃·min⁻¹ for 20 min. The single ion monitoring (SIM) mode was chosen for the quantitative analysis of the 22 VOCs. The method demonstrated good linearity for determining 22 target analytes in the urine of spray painting workers, with correlation coefficients all above 0.990. The lower limits of quantification (LOQ) for the components ranged from 0.4 to 3.8 μg·L⁻¹. The spiked recovery rates of the samples were between 80.1% and 112.1%, and the relative standard deviations (RSD) ranged from 1.5% to 9.7%. All target analytes could be stored at 4 ℃ for 5 d and at −20 ℃ for 7 d. This method was applied to evaluate urine samples from 40 spray painting workers in automotive repair enterprises in Tianjin. The positive rate of butyl acetate was 37.5%. The positive rate of xylene was 32.5%. The positive rate of toluene was 30.0%. The positive rate of isopropanol was 25.0%. The concentration range of the detected substances was from −1. Conclusion The established simultaneous determination protocol of 22 VOCs by static headspace- GC-MS is characterized by its simplicity, high sensitivity, excellent selectivity, and high accuracy. It is suitable for urine samples of spray painting workers in automotive repair industry.

Objective To investigate the effect of subchronic inhalation of toluene diisocyanate (TDI) on oxidative stress damage in rat lung tissue. Methods SPF-grade Sprague-Dawley male rats were randomly divided into 4 groups,the rats were placed in a HOPE-MED 8050A movable poison cabinet in a cage.To observe the ultrastructural and histopathology changes of lung tissue in rats.The levels of reduced glutathione (GSH), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) in lung tissue were detected. The ultrastructural and histopathological changes were examined. The expression levels of HO-1 mRNA and protein were detected by Real-time PCR and Western Blot, respectively. Results The body mass, lung tissue mass, and lung organ coefficient of rats in each dose group were lower than those in the control group (P<0.05), and the body mass of rats in each group increased with the increase of exposure time (P<0.05); The results of lung histopathological examination showed that after TDI exposure,in the high-dose group, pulmonary alveolar wall hyperemia and edema were observed in the lung tissue of rats, alveolar wall thickening was observed, alveolar septa widening, and a large number of red blood cells were seen in the alveolar cavity. The results of ultrastructural examination of lung tissue showed that after TDI exposure, while in the high-dose group, the number of alveolar cells decreased, with unclear cell boundaries and irregular morphology. The levels of MDA in the lung tissue of rats exposed to TDI at various doses were higher than those in the control group (P<0.05), while the levels of GSH, GSH-Px, SOD, and CAT were lower than those in the control group (P<0.05); There was no significant difference in HO-1 gene and protein levels among rats in each group (P>0.05). Conclusion Subchronic inhalation of TDI can cause changes in the pathology and ultrastructure of rat lung tissue, leading to abnormal levels of metabolic enzymes in lung function, thereby inducing oxidative stress damage to the lungs. However, but HO-1 is involved in oxidative stress damage in the lungs induced by TDI.

Background At present, occupational poisoning has become one of the most serious occupational diseases that jeopardize the health of workers in China, in addition to pneumoconiosis, with a wide range of impacts and heavy social and economic losses. Objective To analyze the characteristics and patterns of the incidence of occupational poisoning in Tianjin from 2006 to 2020, and to provide a scientific basis for the development of effective intervention measures and prevention strategies. Methods The Occupational Diseases and Health Hazards Monitoring Information System, a module of the China Disease Prevention and Control Information System, was the primary data source of the study. The case files of acute and chronic occupational poisoning diagnosed by occupational disease diagnostic institutions in Tianjin from January 1, 2006 to December 31, 2020 were retrieved from the system. The data included basic information, occupational history, disease characteristics, and employer information. Excel 2016 was used to establish database, and frequencies and composition ratios were reported. Results From 2006 to 2020, a total of 234 cases of occupational chemical poisoning were reported in Tianjin, including 49 cases of acute occupational poisoning (20.94%) and 185 cases of chronic occupational poisoning (79.06%). The number of acute occupational poisoning cases showed a rising and then falling trend, and the number of chronic occupational poisoning cases showed an overall decreasing trend. Acute occupational poisoning mainly occurred in the four districts around the city (22 cases, 44.90%), and chronic occupational poisoning mainly occurred in Binhai New Area (90 cases, 48.65%). More male cases were reported than female cases. The age of onset was concentrated at 45-55 years old. The acute occupational poisoning cases were concentrated in the group with less than 5 years of service (22 cases, 44.90%), mainly asphyxiating gas poisoning, and the highest incidence was reported in chemical raw materials and chemical products manufacturing industry. The chronic occupational poisoning cases were concentrated in the groups with a working age of 5-14 years (70 cases, 37.84%), mainly organic solvent poisoning, and the highest incidence was also reported in chemical raw materials and chemical products manufacturing industry. Conclusion The prevention and control of occupational poisoning as well as health surveillance and management in Tianjin shall be carried out in a hierarchical and focused manner in accordance with types of acute and chronic occupational poisoning chemicals in the city, regional economic differences, types of industries, and distribution of workers.

Objective To analyze the applicability of different risk assessment methods in assessing laboratory benzenes exposure. Methods The work positions exposed to benzenes (benzene, toluene, xylenes) of a chemical catalyst research and development company were selected as the research subjects. An occupational health field survey was conducted, and the benzenes exposure levels of the lab personnel were measured. Qualitative assessment method, comprehensive index method, quantitative assessment method, and occupational hazards classification method were used to evaluate the occupational health risk on benzenes exposure in the laboratory personnel. The applicability of different assessment methods was compared. Results The occupational health engineering protection measures and management system of the company need to be further implemented. The benzene exposure level of benzene hydrogenation laboratory personnel exceeded the national standard, with the exposure concentration of time weighted average (C_TWA) of 5.00 mg/m³ and short term exposure concentration (C_STE) of 10.50 mg/m³. The C_TWA and C_STE of toluene and xylenes exposure were both lower than the minimum quantitative concentrations. The results of different risk assessment methods varied. The qualitative assessment method indicated higher level of occupational health risk of benzenes, while the comprehensive index and hazard classification methods indicated consistent result on lower level of benzenes. For occupational health risk of benzene, the standardized risk ratio (RR) levels corresponding to the qualitative and quantitative assessment methods were both extremely high risk. The RR levels of benzene exposure assessment using the comprehensive index method and the occupational hazards classification method were high, while the corresponding RR levels of exposure to toluene and xylenes were both low. Conclusion Attention should be paid on the health risks of benzene exposure to benzene hydrogenation laboratory personnel. When benzene exposure level is below the national occupational exposure limit, occupational hazards classification method is not recommended for health risk assessment for benzenes. The comprehensive index method is preferable when more comprehensive occupational health information is available, as it provides a more objective and comprehensive evaluation on occupational health risks of benzenes.

ObjectiveTo explore the mental health status and its influencing factors among middle school students in Xide County， Liangshan Yi Autonomous Prefecture， and to provide references for mental health interventions for local middle school students. MethodsUsing a cross-sectional study design， one junior middle school and one senior middle school in Xide County， Liangshan Prefecture， Sichuan Province， were randomly selected on September 16， 2021， and two classes per grade in each school involving 288 students were recruited. Subjects were assessed using Patients' Health Questionnaire Depression Scale-9 item （PHQ-9）， Generalized Anxiety Disorder Scale-7 item （GAD-7）， PTSD Checklist for DSM-5 （PCL-5）， Multidimensional Scale of Perceived Social Support （MSPSS） and UCLA Loneliness Scale （ULS-3）. Then the scores of above scales were compared among middle school students with different demographic characteristics， and binary Logistic regression analysis was conducted to screen the influencing factors of post-traumatic stress disorder (PTSD） symptoms. ResultsAmong the respondents， 17.71% （95% CI： 0.133~0.221）， 8.68% （95% CI： 0.054~0.120）， 2.78% （95% CI： 0.009~0.047） and 45.83% （95% CI： 0.400~0.516） were reported to have symptoms of depression， anxiety， PTSD and loneliness， respectively. Students in senior middle school scored lower on PCL-5 and ULS-3 than those in junior middle school ［（6.46±8.91） vs. （8.87±9.42）， t=2.202， P<0.05； （4.67±1.65） vs. （5.60±1.88）， t=4.431， P<0.01］. Regression analysis denoted that depressive symptoms （OR=7.630， P<0.05） and anxiety symptoms （OR=3.789， P<0.01） were risk factors for PTSD symptoms among middle school students. ConclusionThe middle school students in Xide County， Liangshan Yi Autonomous Prefecture suffer a high prevalence rate of depressive symptoms and loneliness， and those in junior middle school are more likely to feel a sense of strong loneliness， furthermore， depressive symptoms and anxiety symptoms are risk factors for PTSD symptoms.

Objective To quantify the setup errors for the different anatomical sites of patients who received intensity-modulated radiotherapy (IMRT) with linear accelerator on-board kilovolt fan beam CT(kV-FBCT) as non-isocenter IGRT and megavolt cone beam CT (MV-CBCT) as isocenter IGRT. Methods A retrospective analysis was performedon 70 patients who underwent radiotherapy, kV-FBCT, and/or MV-CBCT scans after each routine setup prior to IMRT. The average displacement (M), systematic error (Σ), and random error (б) at different treatment sites in the left-right, anterior-posterior, and cranial-caudal directions were calculated according to the individual displacements. The formula 2.5Σ+0.7б was used to estimate the PTV margin in respective direction. For each single patient, the root mean square in three directions was used as 3D displacement. Results A total of 1130 displacements were recorded in the 70 patients. The PTV margin was estimated to be 1.9-3.1 mm in head and neck cancer, 2.8-5.1 mm in thoracic cancer, 4.6-5.1 mm in breast cancer, 3.0-5.5 mm in upper abdominal cancer, and 3.5-6.8 mm in pelvic tumor. For the 3D mean displacements, the head and neck, thoracic, breast, upper abdominal, and pelvic cancer were 2.4±1.0, 4.0±1.6, 4.1±2.0, 4.6±2.1, and 4.6±2.1 mm, respectively. The average 3D displacement obtained by kV-FBCT and MV-CBCT were 4.1 and 3.4 mm, respectively (P=0.212). Conclusion The quantitative setup-error data can be obtained using linear accelerator on-board FBCT, and the non-isocenter IGRT induced set-up error cannot be negligible.

Objective To analyze the diagnosis cases of occupational benzene poisoning in gas station industry, and to explore the application of GC-MS technology in occupational disease diagnosis.   Methods The epidemiological method was used to describe and analyze the occupational disease diagnosis of 15 gas station workers , and qualitative screening of occupational hazard factors was performed by GC-MS.   Results All the 15 workers had more than one year's occupation history of oil refueling and unloading.  The clinical manifestations were consistent with the characteristics of chronic benzene poisoning in diagnosis of occupational benzene poisoning.  However, due to lack of evidence of occupational exposure to benzene and incomplete diagnostic data, occupational chronic benzene poisoning was not diagnosed. GC-MS technology was used to screen the occupational hazard factors in the gas station workplace, and benzene, n-pentane, n-hexane and so on were found.  Conclusion GC-MS is recommended for qualitative screening of organic solvents such as benzene when diagnosing occupational diseases for gas station workers , so as to accurately identify occupational hazard factors in workplaces and provide reliable basis for diagnosis of occupational diseases.

Objective To understand the occurrence characteristics of occupational chemical incidents in China by media surveillance, to provide scientific evidences for formulating effective prevention and control strategies, and to provide new ideas for public surveillance and early warning of chemical incidents. Methods Occupational chemical incidents were collected and sorted through the Internet every day. The statistical analysis was conducted from time, region, industry, and causes of the collected incidents. Results A total of 99 occupational chemical incidents were collected in 2021, involving 356 peoples and 186 deaths. April to July was the high incidence period of events, mainly limited space poisoning and asphyxiation events. Majority of the incidents were general grade events, mainly occurring in small and medium enterprises. Guangdong Province had the most incident reporting areas. Incidents mainly occurred in chemical raw material and chemical product manufacturing industry as well as in water production and supply industry, mainly in manufacturing, cleaning and maintenance positions. The main types of poisons were asphyxiating gases and organic solvents, mainly involving hydrogen sulfide and benzene. The incidents could have been caused by lack of safety awareness, leakage of equipment, and lack of protective measures. Conclusion Occupational chemical incidents still occur frequently and cause serious harm. It is suggested that the relevant departments and employers should strengthen supervision and management, effectively manage and control operational risks, and increase supervision of key industries and positions, to ensure the health and safety of workers.

Objective To understand the occupational health status of gas station workers, to analyze the characteristics of early health damage, and to provide a reference for the occupational health monitoring of workers in this industry. Methods The gas station workers who underwent occupational health examination in an occupational health examination institution in Tianjin in 2021were selected as the research subjects. The examination results were statistically analyzed. Results A total of 381 gas station workers were included in this study, with a sex ratio of male to female of 1.40:1. The top three tests with abnormal results from high to low were abdominal color Doppler ultrasound (39.63%), urine routine (29.13%), and blood pressure (23.62%). The detected fatty liver accounted for 74.83% of abnormal abdominal color Doppler ultrasound. Analysis of abnormal results of different genders showed that the detection rate of abnormal blood pressure, fatty liver and liver function in males was higher than that in females (χ²=16.40, 25.40, 15.98，P＜0.05), the detection rate of high GGT in males was significantly higher than that in females (χ²=16.04，P＜0.05）. The detection rate of abnormal urine routine in females was higher than that in males (χ²=12.85，P＜0.05), and the positive rate of urine white blood cells and blood in urine were significantly higher I women than those in men (χ² =16.80, 11.66，P＜0.05). The abnormal detection rate of electrocardiogram of gas station workers increased with age (χ²=28.02，P＜0.05), and the abnormality of high blood pressure showed an increasing trend with age and working years（χ²=25.00, 15.26，P＜0.05). Conclusion The long-term exposure of gas station workers to chemical toxic substances such as organic solvents and benzene series and physical factors such as high temperature in summer and low temperature in winter will have a certain impact on health. It is suggested that employers should reasonably arrange their work systems and carry out occupational health monitoring in a targeted manner.

Objective:To establish a systematic, scientific, reasonable, feasible and reliable evaluation system for occupational disease prevention and control capability, in order to provide reference for occupational disease prevention and control work in Tianjin City.Methods:In August 2022, literature review was conducted to propose indicators for the evaluation system. Two rounds of anonymous consultation with occupational health experts were conducted using the Delphi method to form expert opinions. According to the boundary value method and expert opinions, eliminate, screen, and modify the evaluation system indicators to ultimately determine the system indicators. Use Cronbach's alpha to test the reliability of the system indicators and form a Tianjin occupational disease prevention and control capability evaluation system.Results:It showed that the effective response rates of the two rounds of consultation conducted by experts in this study were 92.3% and 100.0%, respectively. The expert authority coefficients were 0.84 and 0.82, respectively. The Kendall coordination coefficient was tested for differences, and the differences were statistically significant ( P<0.05). The Tianjin occupational disease prevention and control capability evaluation system includes 7 primary indicators, 17 secondary indicators, and 54 tertiary indicators. The Cronbach's alpha of the primary, second, third level indicators and all indicators were 0.91, 0.98, 0.98, 0.98 (>0.7) . Conclusion:The preliminary evaluation system for occupational disease prevention and control capacity in Tianjin City has been established, providing a reference basis for the investigation of occupational disease prevention and control capacity in Tianjin City.